Study: Pesticides Linked to Endometriosis

Researchers believe that there is a potential link between endometriosis and pesticide poisoning.

Endometriosis is a painful gynecological condition in which uterine tissue grows outside the uterus, typically on the exterior of the uterus and into the abdomen near the ovaries or fallopian tubes. The tissue reacts as if it were within the uterus, thickening and shedding monthly with a woman’s menstrual cycle, explained WebMD previously. The condition can lead to scarring and infertility and affects about one in 10 women. Studies suggest that the condition is on the rise. Although its cause is still not known, endometriosis is fed by the female hormone estrogen.

For the recent study, the researchers studied 248 women who were diagnosed with surgically confirmed endometriosis, as well as 538 healthy control subjects—women who had not been diagnosed with endometriosis, according to The New York Times blog Well. The women’s blood levels were tested for two pesticides—mirex and beta HCH. The chemicals still persist in some aquatic life and dairy products, despite that use of these pesticides in the United States has been banned for decades. The study appears in the online journal Environmental Health Perspectives.

The study revealed that women who tested with the highest exposure to mirex also had a 50 percent increased likelihood for being diagnosed with endometriosis; women exposed to high beta HCH levels were diagnosed with a 30-70 percent increased risk of the disorder, according to Well. The tie between the pesticides and endometriosis persisted after adjusting for age, serum lipids, education, race and ethnicity, smoking and alcohol consumption, and other factors, Well reported.

Lead author, Kristen Upson, a pre-doctoral fellow at the Fred Hutchinson Cancer Research Center said that, while the reasons behind the association have not been established, the chemicals do interfere with normal estrogen action in both animal and tissue studies. This interruption offers a potential explanation for endometriosis in humans, according to Well. “Persistent environmental chemicals,” she told Well “even those used in the past, may affect the health of the current generation of reproductive-age women.”

Last year, we wrote that research revealed that benzophenones, chemicals found in some sunscreen and nail polish, had been linked to endometriosis. The study was published in Environmental Science & Technology. The research measured concentrations of five benzophenone chemicals in the urine of more than 600 women evaluated for endometriosis, said WebMD. In small doses, benzophenones are used to protect against UV light in products such as nail polish, while, in greater levels, they can be found in sunscreens. Benzophenones are easily absorbed through the skin and are be found in 97 percent of the people tested, according to studies conducted by the U.S. Centers for Disease Control and Prevention (CDC).

Scientists worry that the body may mistake benzophenones for hormones. “These compounds are estrogenic. They mimic estrogen in the body,” researcher Kurunthachalam Kannan, PhD, a professor of public health and environmental health sciences with the New York State Department of Health’s Wadsworth Center in Albany, told WebMD at the time. Kannan explained that benzophenone-3 appears on sunscreen labels as oxybenzone and is even more estrogenic than the very estrogenic polycarbonate plastics chemical, bisphenol A (BPA).

The study found that benzophenone-1 was significantly associated with increased risks for endometriosis and that women with the highest level of this chemical in their urine—65 percent or more—had the greatest likelihood for the disorder, according to WebMD. A chemical additive mostly used in nail polishes, benzophenone-1 also forms when the body breaks down oxybenzone, a key ingredient in sunscreen. Oxybenzone can cause skin irritation, said WebMD.

We have also long written that studies have suggested a link between various pesticides and Parkinson’s disease. Parkinson’s disease is a progressive, degenerative central nervous system disorder that typically affects motor skills and speech, among other functions and, while not fatal, complications can be deadly. The cause is unknown and there is no cure.